//https://leetcode.cn/problems/flood-fill/

class Solution {
    int dx[4] = { 0,0,-1,1 };
    int dy[4] = { -1,1,0,0 };
public:
    vector<vector<int>> floodFill(vector<vector<int>>& image, int sr, int sc, int color) {
        int prev = image[sr][sc];
        if (prev == color) return image;

        queue<pair<int, int>> q;
        q.push({ sr,sc });

        while (q.size())
        {
            auto [a, b] = q.front();
            image[a][b] = color;
            q.pop();

            for (int i = 0; i < 4; i++)
            {
                int x = a + dx[i];
                int y = b + dy[i];
                if (x >= 0 && x < image.size() && y >= 0 && y < image[0].size() && image[x][y] == prev)
                {
                    q.push({ x,y });
                }
            }
        }

        return image;

    }
};